<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
    <style>
      span {
        background-color: yellow;
      }
      .one {
        margin-left: 20px;
        padding-left: 30px;
        /* 没生效 */
        margin-top: 50px;
        margin-bottom: 50px;
        /* 生效了但是没挤开下面的元素 */
        padding-bottom: 60px;
      }
      .bottom {
        background-color: red;
      }
      /* 
      结论:行内块盒子的margin和padding只对水平方向起作用,对垂直方向不起作用,如果想让垂直方向也生效,需要给元素设置display:inline-block;
      */
    </style>
  </head>
  <body>
    <span class="one">我是1</span>
    <span>我是2</span>
    <span>我是三</span><br />
    <span class="bottom">我在下面</span>
  </body>
</html>
